U.S. patent application number 16/091876 was filed with the patent office on 2019-05-02 for additive manufacturing system.
This patent application is currently assigned to Siemens Aktiengesellschaft. The applicant listed for this patent is Siemens Aktiengesellschaft. Invention is credited to Andreas GRAICHEN, Pontus JOHANSSON, Eva NORDENBERG, Anders PERSSON.
Application Number | 20190126346 16/091876 |
Document ID | / |
Family ID | 56068665 |
Filed Date | 2019-05-02 |
United States Patent
Application |
20190126346 |
Kind Code |
A1 |
GRAICHEN; Andreas ; et
al. |
May 2, 2019 |
ADDITIVE MANUFACTURING SYSTEM
Abstract
An additive manufacturing system having at least one powder
based additive manufacturing machine having a build chamber, at
least one stationary powder storage container, and a powder feeding
device for feeding powder from the at least one powder storage
container into the build chamber. The build chamber, stationary
powder storage container and powder feeding device form a part of a
powder handling system, which is hermetically sealable in a
powder-tight manner and to which a movable powder storage container
is connected. The powder handling system selectively feeds powder
from the movable powder storage container to the stationary powder
storage container or removes powder from the build chamber in the
hermetically sealed state. A method for feeding powder into and
removing powder from a build chamber of at least one additive
manufacturing machine, where the feeding and the removal of the
powder takes place within a hermetically sealable powder handling
system.
Inventors: |
GRAICHEN; Andreas;
(Norrkoping, SE) ; JOHANSSON; Pontus; (Lotorp,
SE) ; NORDENBERG; Eva; (Norrkoping, SE) ;
PERSSON; Anders; (Lotorp, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Siemens Aktiengesellschaft |
Munich |
|
DE |
|
|
Assignee: |
Siemens Aktiengesellschaft
Munich
DE
|
Family ID: |
56068665 |
Appl. No.: |
16/091876 |
Filed: |
May 4, 2017 |
PCT Filed: |
May 4, 2017 |
PCT NO: |
PCT/EP2017/060684 |
371 Date: |
October 5, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B22F 3/003 20130101;
Y02P 10/24 20151101; Y02P 10/25 20151101; B29C 64/25 20170801; B33Y
30/00 20141201; Y02P 10/295 20151101; B29C 64/20 20170801; B22F
3/1055 20130101; B22F 2003/1059 20130101; Y02P 10/20 20151101; B33Y
40/00 20141201; B22F 2003/1056 20130101; B29C 64/153 20170801; B33Y
10/00 20141201; B29C 64/321 20170801 |
International
Class: |
B22F 3/00 20060101
B22F003/00; B22F 3/105 20060101 B22F003/105; B33Y 10/00 20060101
B33Y010/00; B33Y 30/00 20060101 B33Y030/00; B33Y 40/00 20060101
B33Y040/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 9, 2016 |
EP |
16168715.7 |
Claims
1. An additive manufacturing system comprising: at least one powder
based additive manufacturing machine having a build chamber, at
least one stationary powder storage container, and a powder feeding
device for feeding powder from the at least one stationary powder
storage container into the build chamber, wherein said build
chamber, said stationary powder storage container and said powder
feeding device form a part of a powder handling system, which is
hermetically sealable in a powder-tight manner and to which a
movable powder storage container is connected, said powder handling
system being designed to selectively feed powder from the movable
powder storage container to the stationary powder storage container
or to remove powder from the build chamber in a hermetically sealed
state.
2. The additive manufacturing system according to claim 1, wherein
said powder handling system comprises a first powder conveyor pipe
for feeding powder from said movable powder storage container to
said stationary powder storage container, a second powder conveyor
pipe for removing powder from the build chamber and a vacuum pump
designed to be selectively connected to said first powder conveyor
pipe or said second powder conveyor pipe by corresponding
valves.
3. The additive manufacturing system according to claim 1, wherein
said powder handling system comprises a sieving device designed and
arranged for sieving the powder received from the movable powder
storage container and/or removed from the build chamber, and/or a
bucket for oversized material is provided, which is connected to
said sieving device.
4. The additive manufacturing system according to claim 3, wherein
said powder handling system comprises an intermediate powder
storage container arranged downstream the sieving device for
receiving sieved powder from the sieving device.
5. The additive manufacturing system according to claim 4, wherein
the intermediate powder storage container is connected to a
vibrator device and/or comprises a heating device for heating
received powder.
6. The additive manufacturing system according to claim 4, wherein
a second movable bucket is connectable to a downstream side of the
intermediate powder storage container.
7. The additive manufacturing system according to claim 1, wherein
said stationary powder storage container is connected to a vibrator
device and/or comprises a weighing device and/or comprises a mixing
device.
8. The additive manufacturing system according to claim 2, wherein
the second powder conveyor pipe is coupled to a suction hose, which
is arranged within the build chamber and is manually movable by an
operator, from a front of the additive manufacturing machine, by
reaching into said build chamber.
9. The additive manufacturing system according to claim 1, wherein
said powder handling system comprises a feeding station having a
hermetically sealable cabin for receiving the movable powder
storage container.
10. The additive manufacturing system according to claim 1, further
comprising: several additive manufacturing machines forming one
single powder handling system.
11. A method for feeding powder into and removing powder from a
build chamber of at least one additive manufacturing machine, the
method comprising: feeding and removing of the powder within a
powder handling system according to claim 1.
12. The method according to claim 11, further comprising: treating
used powder removed from said additive manufacturing machine,
within said powder handling system and thereafter reusing within
said or another additive manufacturing machine coupled to the
powder handling system.
13. The additive manufacturing system according to claim 4, wherein
the stationary powder storage container, the sieving device, and
the intermediate powder storage container are connected to each
other to form a closed-loop powder recycling arrangement.
14. The additive manufacturing system according to claim 8, further
comprising: gloves for reaching into said build chamber.
15. The additive manufacturing system according to claim 9, wherein
the cabin comprises a suction hose, which is arranged within the
cabin and is manually movable by an operator, from the front of the
cabin with gloves, by reaching into said cabin.
16. The method according to claim 12, wherein the used powder is
treated by sieving.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2017/060684 filed May 4, 2017, and claims the
benefit thereof. The International Application claims the benefit
of European Application No. EP16168715 filed May 9, 2016. All of
the applications are incorporated by reference herein in their
entirety.
FIELD OF INVENTION
[0002] The present invention relates to an additive manufacturing
system comprising at least one powder based additive manufacturing
machine having a build chamber, at least one stationary powder
storage container, and a powder feeding device for feeding powder
from the at least one powder storage container into the build
chamber.
BACKGROUND OF INVENTION
[0003] Various types of powder based additive manufacturing systems
of the above-mentioned kind are already known, such as for electron
beam melting or laser additive manufacturing. They all have in
common that a workpiece is build up in layers on the basis of a
powder, in particular a metallic powder. Such processes are also
designated as 3D-printing processes.
[0004] There is currently a high risk for operators handling the
powder when operating additive manufacturing systems, in particular
when manually filling and emptying its stationary powder storage
container. The fine powder particles infiltrate the ambient air and
are breathed in by the operators leading to serious health
impairment. Moreover, the powder itself can be deteriorated or
contaminated by the ambient air causing defects in the manufactured
components.
SUMMARY OF INVENTION
[0005] Against this background it is an object of the present
invention to provide an improved additive manufacturing system of
the above-mentioned kind.
[0006] In order to solve this object the present invention provides
an additive manufacturing system of the above-mentioned kind, which
is characterized in that said build chamber, said stationary powder
storage container and said powder feeding device form a part of a
powder handling system, which is hermetically sealable in a
powder-tight manner and to which a movable powder storage container
containing fresh powder can be connected, said powder handling
system being designed to selectively feed powder from the movable
powder storage container to the stationary powder storage container
or to remove powder from the build chamber in the hermetically
sealed state. Thanks to such a hermetically sealable powder
handling system, in which all components transporting or storing
powder are sealable in a powder-tight manner at least during the
normal operation of the system, it is effectively prevented that
the metallic powder particles can infiltrate the ambient air or can
be deteriorated or contaminated by the ambient air. Accordingly,
there is neither a health risk for operators, who handle the
additive manufacturing system of the present invention, nor a risk
of deterioration of the workpiece quality due to adverse influences
of the environment over the powder.
[0007] According to one aspect of the present invention said powder
handling system comprises a first powder conveyor pipe for feeding
powder from said movable powder storage container to said
stationary powder storage container, a second powder conveyor pipe
for removing powder from the build chamber, and a vacuum pump
designed to be selectively connected to said first powder conveyor
pipe or said second powder conveyor pipe by means of corresponding
valves. This leads to a simple and inexpensive structure of the
powder handling system.
[0008] Advantageously said powder handling system comprises a
sieving device designed and arranged for sieving the powder
received from the movable powder storage container and/or removed
from the build chamber, whereas a bucket for oversized material is
advantageously provided, which can be connected to said sieving
device. Thanks to such a sieving device oversized material present
in the fresh powder received from the movable powder storage
container or present in the used powder removed from the build
chamber is withdrawn and collected in a separate bucket. As a
consequence, the powder can be used again without deteriorating the
quality of the next build-up process.
[0009] The powder handling system advantageously comprises an
intermediate powder storage container arranged downstream the
sieving device for receiving sieved powder from the sieving device,
wherein the stationary powder storage container, the sieving device
and the intermediate powder storage container are advantageously
connected to each other to form a closed-loop powder recycling
arrangement for recycling used powder in order to use it once again
in the additive manufacturing machine.
[0010] According to one aspect of the present invention the
intermediate powder storage container is connected to a vibrator
device and/or comprises a heating device for heating received
powder and/or a mixing device for mixing received powder. A
vibrator device facilitates an emptying of the intermediate powder
storage container. A heating device enables a preheating of the
powder to a desired temperature and a drying of the powder before
delivering the powder to the build chamber in order to optimize the
next build-up process. Advantageously, the heating device is
designed to preheat the powder contained therein to some
100.degree. C., in particular to a temperature between 100.degree.
C. and 300.degree. C. A mixing device prevents the formation of
powder layers having different grain sizes.
[0011] Advantageously a second movable bucket is connectable to a
downstream side of the intermediate powder storage container in
order to receive used powder, which is not to be used once more in
the additive manufacturing operation, which needs to be stored
intermediately during maintenance work or the like, etc. As the
movable powder storage container, the second movable bucket is
advantageously connectable to the powder handling system as well as
openable and closable in a powder-tight manner.
[0012] According to one aspect of the present invention said
stationary powder storage container is connected to a vibrator
device and/or comprises a weighing device and/or comprises a mixing
device. A vibrator device facilitates an emptying of the stationary
powder storage container. The weighing device is designed to weight
the powder stored in the stationary powder storage container. On
the basis of the weight it can be determined how much powder has to
be delivered to the stationary powder storage container after one
operating cycle in order to perform the next operating cycle. A
mixing device prevents the formation of powder layers having
different grain sizes.
[0013] The second powder conveyor pipe is advantageously coupled to
a suction hose, which is arranged within the build chamber and is
manually movable by an operator, who stands in front of the
additive manufacturing machine, in particular by means of gloves
reaching into said build chamber. Such a suction hose is very
comfortable to handle by the operator in order to remove powder
from the build chamber.
[0014] Advantageously, said powder handling system comprises a
feeding station having a hermetically sealable cabin for receiving
the at least one movable powder storage container, said cabin
advantageously comprises a suction hose, which is arranged within
the cabin and is manually movable by an operator, who stands in
front of the cabin, in particular by means of gloves reaching into
said cabin. Such a feeding station facilitates the feeding of fresh
powder to the powder handling system.
[0015] The additive manufacturing system according to the present
invention advantageously comprises several additive manufacturing
machines forming one single powder handling system. In this
context, the vacuum pump, the sieving device and an intermediate
powder storage container may form a central powder treatment unit,
which can be used by all additive manufacturing machines.
[0016] In order to solve the above-mentioned object, the present
invention further provides a method for feeding powder into and
removing powder from a build chamber of at least one additive
manufacturing machine, which is characterized in that the feeding
and the removal of the powder takes place within a hermetically
sealable powder handling system.
[0017] According to one aspect used powder is removed from said
additive manufacturing machine, is treated, in particular by
sieving, within said sealed powder handling system and is
thereafter reused within said or another additive manufacturing
machine coupled to the powder handling system. In other words, used
powder is recycled within the system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Further features and aspects of the present invention will
become apparent to a skilled person from the following description
of an embodiment of an additive manufacturing system according to
the present invention with reference to the accompanying drawing.
In the drawing
[0019] FIG. 1 is a front view of an embodiment of an additive
manufacturing system according to the present invention;
[0020] FIG. 2 is a top view of the additive manufacturing system
shown in FIG. 1;
[0021] FIG. 3 is a side view of the additive manufacturing system
shown in FIG. 1;
[0022] FIG. 4 is an enlarged front view of a first arrangement of
the additive manufacturing system shown on the left side of FIG.
1;
[0023] FIG. 5 is a side view of the first arrangement shown in FIG.
4;
[0024] FIG. 6 is a rear view of second arrangement of the additive
manufacturing system shown on the side of FIG. 1;
[0025] FIG. 7 is a side view of the second arrangement shown in
FIG. 6;
[0026] FIG. 8 is a front view of a feeding station of the additive
manufacturing system shown on the left side of FIG. 3;
[0027] FIG. 9 is a top view of the feeding station;
[0028] FIG. 10 is a cross-sectional view of the feeding station
along line X-X in FIG. 8 and
[0029] FIG. 11 is a cross-sectional view of the feeding station
along line XI-XI in FIG. 9.
DETAILED DESCRIPTION OF INVENTION
[0030] The drawing shows an additive manufacturing system 1
according to an embodiment of the present invention. The additive
manufacturing system 1 comprises a powder based additive
manufacturing machine 2, such as for electron beam melting or laser
additive manufacturing, having a build chamber 3. In order to
supply the build chamber 3 with powder, a stationary powder storage
container 4 is positioned above the additive manufacturing machine
2. According to the present embodiment the storage container 4 is
fixed to a framework 5 positioned right next to the additive
manufacturing machine 2 as shown in detail in FIGS. 6 and 7.
However, it is also possible to integrate the storage container 4
in the additive manufacturing machine 2. The storage container 4 is
connected to a feeding device 6, which is adapted to batchwise feed
powder into the build chamber 3. For this a Y-shaped feeding pipe 7
connects the feeding device 6 with the build chamber 3. The storage
container 4 is provided with a vibrator device 8 in order to assist
the discharging of the storage container 4. Moreover, the storage
container 4 rests on a weighing device 9 in order to weight the
powder stored in the storage container 4. Furthermore, the storage
container 4 may be equipped with a mixing device (not shown), such
as a mixing screw, in order to mix the powder contained in the
powder storage container 4. Such a mixing device can prevent the
formation of powder layers having different grain sizes.
[0031] As a further component of the additive manufacturing system
1 a central powder treatment unit 10 is provided, which is shown in
detail in FIGS. 4 and 5. The powder treatment unit 10 comprises a
framework 11 receiving--from the top to the bottom--a vacuum pump
12, a valve 13 connecting the vacuum pump to a flexible coupling
joint 14, a sieving device 15 connected to the flexible coupling
joint 14, a second flexible coupling joint 16 connecting the
sieving device 15 with an intermediate storage container 17, and a
valve 18 connecting the intermediate storage container 17 with a
third flexible coupling joint 19. The vacuum pump 12 is connected
to the stationary powder storage container 4 via a vacuum pipe 20.
The sieving device 15 is provided with a branch pipe 21, through
which oversized material sieved out by the sieving device 15 can be
discharged in a separate movable bucket 22. The intermediate powder
storage container 17 is connected to a vibrator device 23 for
oscillating the container 17 as well as with a heating device 24
for heating the powder stored in the container 17. The third
flexible coupling joint 19 is connected to the stationary powder
storage container 4 of the additive manufacturing machine 2 via a
first powder conveyor pipe 25. Moreover, the flexible coupling
joint 19 is designed to be connected to a movable bucket 26 placed
at the bottom of the powder treatment unit 10 beneath the flexible
coupling joint 19. Even though not shown, the movable bucket 26 may
be arranged as it is described subsequently for a movable powder
storage container 31, in a separate feeding station allowing a
handling, in particular a connecting, opening and closing of the
movable bucket 26 in a powder-tight manner. The flexible coupling
joint 14, which is placed directly above the sieving device 15, can
be selectively coupled by means of the valve 13 with a second
powder conveyor pipe 27 leading to the stationary powder storage
container 4 of the additive manufacturing machine 2 or with a
suction pipe 28 leading to a feeding station 29.
[0032] The feeding station 29, which is shown in detail in FIGS. 8
to 11, comprises a hermetically sealable cabin 30 designed for
receiving several movable powder storage containers 31 containing
fresh powder. The cabin 30 comprises an inspection window 32 and a
front door 33 being provided with openings 35 to which gloves 34
are fixed for reaching inside the cabin 30. Accordingly, an
operator can handle objects present within the cabin 30 without
opening the front door 33. Within the cabin 30 a suction hose 36 is
provided, which is connected to the suction pipe 28 connected to
the flexible coupling joint 14 of the powder treatment unit 10. The
cabin 30 is placed on a movable table 37 provided with rolls
38.
[0033] According to the present invention the build chamber 3, the
stationary power storage container 4, the feeding device 6, the
powder treatment unit 10 and the cabin 30 form a hermetically
sealable powder handling system being designed to selectively feed
powder from one of the movable powder storage containers 31
received in the cabin 30 to the stationary powder storage container
4 of the additive manufacturing machine 2 or to remove powder form
the build chamber 3 without the possibility, that powder can
infiltrate the ambient air during these operations.
[0034] For filling up the stationary powder storage container 4
with fresh powder, movable powder storage containers 31 containing
such fresh powder are placed in the cabin 30 by opening and closing
the front door 33. After closing the front door 33, the powder
handling system is hermetically sealed. Then, the vacuum pump 12 is
started, whereupon an operator can suck the fresh powder present in
one of the movable powder storage containers 31 by means of the
suction hose 36 through the suction pipe 28 and the flexible
coupling joint 14 into the sieving device 15. The sieving device 15
sieves the fresh powder and removes oversized material into the
bucket 22. The remaining powder falls through the second flexible
coupling joint 16 into the intermediate powder storage container
17, in which the powder is heated to a desired temperature in order
to pre-tempering the powder to a desired temperature,
advantageously between 100.degree. C. and 300.degree. C., and to
reduce the moisture content of the powder. Afterwards the powder is
transported to the stationary powder storage container 4 via the
first powder conveyor pipe 25. Subsequently the additive
manufacturing machine 2 can be operated, whereupon the needed
powder is delivered by means of the feeding device 6 from the
storage container 4 into the build chamber 3 via the feeding pipe
7. For this purpose, a rotary valve may be provided between the
stationary powder storage container 4 and the build chamber 3.
[0035] As soon as the operation of the additive manufacturing
machine 2 is completed, a suction hose (not shown) can be coupled
to the feeding pipe 7 to suck the remaining powder present in the
build chamber 3 of the additive manufacturing machine to the
sieving device 15 via a branch pipe of the Y-shaped feeding pipe 7,
the second powder conveyor pipe 27 and the flexible coupling joint
14. In the sieving device 15 oversized powder is removed in the
bucket 22, whereas the remaining powder is stored and heated in the
intermediate powder storage container 17.
[0036] In order to empty the intermediate storage container 17, the
movable bucket 26 can be connected to the flexible coupling joint
19 arranged underneath the intermediate powder storage container
17.
[0037] Moreover, powder samples can be retrieved for quality
control without a need for the operator to contact the powder.
[0038] A main advantage of the additive manufacturing system 1
consists in the eliminated health risk for operators handling the
metallic powder when operating the additive manufacturing system 1.
Moreover, the powder itself cannot be deteriorated or contaminated
by the ambient air. Accordingly, defects in the manufactured
components caused by such deterioration or contamination are
prevented. Furthermore, the additive manufacturing system 1 allows
the recycling of used powder within a closed and powder-tight loop
arrangement.
[0039] It should be noted that the above-described embodiment
serves only as an example, and that modifications are possible
without leaving the scope of protection defined by the accompanying
claims. In particular, a plurality of additive manufacturing
machines can be connected to the central powder treatment unit 10
and to the feeding station 29 in the above-described manner.
Moreover, instead of the vacuum pump 12 another powder conveyor can
be used, such as a screw conveyor or the like.
* * * * *